Muscle Actions Flashcards
Closes and puckers lips
Orbicularis oris
Pulls angle of mouth upwards
Zygomaticus
Helps masseter raise the mandible
Temporalis
Compresses cheeks
Buccinator
Pair of Neck muscles that flex head
Sternocleidomastoid
Pair of muscles that extend head
Splenius capitus
Innermost muscle of abdominal wall
Transversus abdominis
Raises ribs during inspiration
external intercostals
Elevates Clavicle and scapula
Trapezius
Draws scapula downward and anteriorly
Pectoralis minor
Adducts and draws humerus across chest
pectoralis major
Sheetlike muscle of lower back that adducts and extends humerus
Latissimus dorsi
Abducts, flexes and extend humerus
Deltoid
flexion vs. extension of shoulder
Flexion is forward Extension is backwards

Rotates humerus laterally
Infraspinatus
Assists Deltoid in abducting Humerus
Supraspinatus
Rotator Cuff muscles (4) (S.I.T.S), function, Location (O-I)
1) Infraspinatus (I = greater tubercle humerus)
2) Supraspinatus (I = greater tubercle humerus)
3) Subscapularis (I = lesser tubercle humerus)
4) Teres Minor (I = greater tubercle humerus. O = Lateral border of scapula)
Stabilizing the shoulder, also elevates and rotates the arm.
Each muscle originates on the scapula, and inserts on the humerus.
Assists Lasissimus Dorsi
Teres major
Assists biceps brachii (2 muscles)
Brachialis Brachioradialis
Extends forearm
Triceps brachii
Flexes and rotates forearm laterally
Biceps brachii
Flexes and abducts wrist
Flexor carpi radialis
Flexes and adducts wrist
Flexor carpi ulnaris
Adducts, flexes, and rotates thigh laterally (3 muscles)
Adductor Longus, Adductor Magnus, Adductor brevis
Abducts and rotates thigh medially
Gluteus medius
Extends and rotates thigh laterally
Gluteus Maximus
Extension vs. Flexion of thigh
Extension towards back
Flexion towards front

Flexes and abducts thigh
Tensor fasciae Latae
Flexes thigh only (2 muscles)
Iliacus
Psoas major
Flexes leg and thigh
Sartorius
Flexes leg and adducts thigh
Gracilis
Group of four muscles that extend leg
Quadriceps Femoris (1)Biceps Femoris, 2)Vastus lateralis, 3)Vastus Medialis, 4)Vastus intermedius = main function is knee extension)
Knee Extension [1, 2, 3, 4]
Hip Flexion [1]
O = Illiac Spine [1] Grater throcanter [2] Interthrocanteric line [3], Anterior proximal Surface femur [4]
I = Tibia Tuberosity [1, 2, 3, 4] through Patellar Tendon

Three muscles that flex the leg and extends thigh
- Biceps femoris
- Semitendinosus
- Semimembranosus

Dorsiflexes and Inverts foot
Tibialis anterior

Flexes leg and plantar flexes foot
Gastrocnemius

Extends Toes and dorsiflexes and everts foot
Extensor digitorum longus
Plantar flexes and everts foot
Fibularis longus
